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/******************************************************************************
* grant_table.c
* x86 specific part
*
* Granting foreign access to our memory reservation.
*
* Copyright (c) 2005-2006, Christopher Clark
* Copyright (c) 2004-2005, K A Fraser
* Copyright (c) 2008 Isaku Yamahata <yamahata at valinux co jp>
* VA Linux Systems Japan. Split out x86 specific part.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License version 2
* as published by the Free Software Foundation; or, when distributed
* separately from the Linux kernel or incorporated into other
* software packages, subject to the following license:
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this source file (the "Software"), to deal in the Software without
* restriction, including without limitation the rights to use, copy, modify,
* merge, publish, distribute, sublicense, and/or sell copies of the Software,
* and to permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
* IN THE SOFTWARE.
*/
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <xen/interface/xen.h>
#include <xen/page.h>
#include <xen/grant_table.h>
#include <xen/xen.h>
#include <asm/pgtable.h>
static struct gnttab_vm_area {
struct vm_struct *area;
pte_t **ptes;
} gnttab_shared_vm_area, gnttab_status_vm_area;
int arch_gnttab_map_shared(unsigned long *frames, unsigned long nr_gframes,
unsigned long max_nr_gframes,
void **__shared)
{
void *shared = *__shared;
unsigned long addr;
unsigned long i;
if (shared == NULL)
*__shared = shared = gnttab_shared_vm_area.area->addr;
addr = (unsigned long)shared;
for (i = 0; i < nr_gframes; i++) {
set_pte_at(&init_mm, addr, gnttab_shared_vm_area.ptes[i],
mfn_pte(frames[i], PAGE_KERNEL));
addr += PAGE_SIZE;
}
return 0;
}
int arch_gnttab_map_status(uint64_t *frames, unsigned long nr_gframes,
unsigned long max_nr_gframes,
grant_status_t **__shared)
{
grant_status_t *shared = *__shared;
unsigned long addr;
unsigned long i;
if (shared == NULL)
*__shared = shared = gnttab_status_vm_area.area->addr;
addr = (unsigned long)shared;
for (i = 0; i < nr_gframes; i++) {
set_pte_at(&init_mm, addr, gnttab_status_vm_area.ptes[i],
mfn_pte(frames[i], PAGE_KERNEL));
addr += PAGE_SIZE;
}
return 0;
}
void arch_gnttab_unmap(void *shared, unsigned long nr_gframes)
{
pte_t **ptes;
unsigned long addr;
unsigned long i;
if (shared == gnttab_status_vm_area.area->addr)
ptes = gnttab_status_vm_area.ptes;
else
ptes = gnttab_shared_vm_area.ptes;
addr = (unsigned long)shared;
for (i = 0; i < nr_gframes; i++) {
set_pte_at(&init_mm, addr, ptes[i], __pte(0));
addr += PAGE_SIZE;
}
}
static int arch_gnttab_valloc(struct gnttab_vm_area *area, unsigned nr_frames)
{
area->ptes = kmalloc(sizeof(pte_t *) * nr_frames, GFP_KERNEL);
if (area->ptes == NULL)
return -ENOMEM;
area->area = alloc_vm_area(PAGE_SIZE * nr_frames, area->ptes);
if (area->area == NULL) {
kfree(area->ptes);
return -ENOMEM;
}
return 0;
}
static void arch_gnttab_vfree(struct gnttab_vm_area *area)
{
free_vm_area(area->area);
kfree(area->ptes);
}
int arch_gnttab_init(unsigned long nr_shared, unsigned long nr_status)
{
int ret;
if (!xen_pv_domain())
return 0;
ret = arch_gnttab_valloc(&gnttab_shared_vm_area, nr_shared);
if (ret < 0)
return ret;
/*
* Always allocate the space for the status frames in case
* we're migrated to a host with V2 support.
*/
ret = arch_gnttab_valloc(&gnttab_status_vm_area, nr_status);
if (ret < 0)
goto err;
return 0;
err:
arch_gnttab_vfree(&gnttab_shared_vm_area);
return -ENOMEM;
}
#ifdef CONFIG_XEN_PVH
#include <xen/balloon.h>
#include <xen/events.h>
#include <linux/slab.h>
static int __init xlated_setup_gnttab_pages(void)
{
struct page **pages;
xen_pfn_t *pfns;
int rc;
unsigned int i;
unsigned long nr_grant_frames = gnttab_max_grant_frames();
BUG_ON(nr_grant_frames == 0);
pages = kcalloc(nr_grant_frames, sizeof(pages[0]), GFP_KERNEL);
if (!pages)
return -ENOMEM;
pfns = kcalloc(nr_grant_frames, sizeof(pfns[0]), GFP_KERNEL);
if (!pfns) {
kfree(pages);
return -ENOMEM;
}
rc = alloc_xenballooned_pages(nr_grant_frames, pages, 0 /* lowmem */);
if (rc) {
pr_warn("%s Couldn't balloon alloc %ld pfns rc:%d\n", __func__,
nr_grant_frames, rc);
kfree(pages);
kfree(pfns);
return rc;
}
for (i = 0; i < nr_grant_frames; i++)
pfns[i] = page_to_pfn(pages[i]);
rc = arch_gnttab_map_shared(pfns, nr_grant_frames, nr_grant_frames,
&xen_auto_xlat_grant_frames.vaddr);
if (rc) {
pr_warn("%s Couldn't map %ld pfns rc:%d\n", __func__,
nr_grant_frames, rc);
free_xenballooned_pages(nr_grant_frames, pages);
kfree(pages);
kfree(pfns);
return rc;
}
kfree(pages);
xen_auto_xlat_grant_frames.pfn = pfns;
xen_auto_xlat_grant_frames.count = nr_grant_frames;
return 0;
}
static int __init xen_pvh_gnttab_setup(void)
{
if (!xen_pvh_domain())
return -ENODEV;
return xlated_setup_gnttab_pages();
}
/* Call it _before_ __gnttab_init as we need to initialize the
* xen_auto_xlat_grant_frames first. */
core_initcall(xen_pvh_gnttab_setup);
#endif
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